    001    /* ===========================================================
    002     * JFreeChart : a free chart library for the Java(tm) platform
    003     * ===========================================================
    004     *
    005     * (C) Copyright 2000-2007, by Object Refinery Limited and Contributors.
    006     *
    007     * Project Info:  http://www.jfree.org/jfreechart/index.html
    008     *
    009     * This library is free software; you can redistribute it and/or modify it
    010     * under the terms of the GNU Lesser General Public License as published by
    011     * the Free Software Foundation; either version 2.1 of the License, or
    012     * (at your option) any later version.
    013     *
    014     * This library is distributed in the hope that it will be useful, but
    015     * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
    016     * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
    017     * License for more details.
    018     *
    019     * You should have received a copy of the GNU Lesser General Public
    020     * License along with this library; if not, write to the Free Software
    021     * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
    022     * USA.
    023     *
    024     * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
    025     * in the United States and other countries.]
    026     *
    027     * -----------------
    028     * ChartDeleter.java
    029     * -----------------
    030      * (C) Copyright 2002-2007, by Richard Atkinson and Contributors.
    031     *
    032     * Original Author:  Richard Atkinson;
    033     * Contributor(s):   -;
    034     *
    035     * $Id: ChartDeleter.java,v 1.2.2.3 2007/02/02 15:03:19 mungady Exp $
    036     *
    037     * Changes
    038     * -------
    039     * 19-Aug-2002 : Version 1;
    040     * 17-Oct-2002 : Fixed errors reported by Checkstyle (DG);
    041     * ------------- JFREECHART 1.0.x ---------------------------------------------
    042     * 02-Feb-2007 : Removed author tags all over JFreeChart sources (DG);
    043     *
    044     */
    045    package org.jfree.chart.servlet;
    046
    047    import java.io.File;
    048    import java.io.Serializable;
    049    import java.util.Iterator;
    050    import java.util.List;
    051
    052    import javax.servlet.http.HttpSessionBindingEvent;
    053    import javax.servlet.http.HttpSessionBindingListener;
    054
    055    /**
    056     * Used for deleting charts from the temporary directory when the users session
    057     * expires.
    058     */
    059    public class ChartDeleter implements HttpSessionBindingListener, Serializable {
    060
    061        /** The chart names. */
    062        private List chartNames = new java.util.ArrayList();
    063
    064        /**
    065         * Blank constructor.
    066         */
    067        public ChartDeleter() {
    068            super();
    069        }
    070
    071        /**
    072         * Add a chart to be deleted when the session expires
    073         *
    074         * @param filename  the name of the chart in the temporary directory to be
    075         *                  deleted.
    076         */
    077        public void addChart(String filename) {
    078            this.chartNames.add(filename);
    079        }
    080
    081        /**
    082         * Checks to see if a chart is in the list of charts to be deleted
    083         *
    084         * @param filename  the name of the chart in the temporary directory.
    085         *
    086         * @return A boolean value indicating whether the chart is present in the
    087         *         list.
    088         */
    089        public boolean isChartAvailable(String filename) {
    090            return (this.chartNames.contains(filename));
    091        }
    092
    093        /**
    094         * Binding this object to the session has no additional effects.
    095         *
    096         * @param event  the session bind event.
    097         */
    098        public void valueBound(HttpSessionBindingEvent event) {
    099            return;
    100        }
    101
    102        /**
    103         * When this object is unbound from the session (including upon session
    104         * expiry) the files that have been added to the ArrayList are iterated
    105         * and deleted.
    106         *
    107         * @param event  the session unbind event.
    108         */
    109        public void valueUnbound(HttpSessionBindingEvent event) {
    110
    111            Iterator iter = this.chartNames.listIterator();
    112            while (iter.hasNext()) {
    113                String filename = (String) iter.next();
    114                File file = new File(
    115                    System.getProperty("java.io.tmpdir"), filename
    116                );
    117                if (file.exists()) {
    118                    file.delete();
    119                }
    120            }
    121            return;
    122
    123        }
    124
    125    }